//download.js v3.0, by dandavis; 2008-2014. [CCBY2] see http://danml.com/download.html for tests/usage
// v1 landed a FF+Chrome compat way of downloading strings to local un-named files, upgraded to use a hidden frame and optional mime
// v2 added named files via a[download], msSaveBlob, IE (10+) support, and window.URL support for larger+faster saves than dataURLs
// v3 added dataURL and Blob Input, bind-toggle arity, and legacy dataURL fallback was improved with force-download mime and base64 support

// data can be a string, Blob, File, or dataURL


export function download(data, strFileName, strMimeType) {

  var self = window, // this script is only for browsers anyway...
    u = "application/octet-stream", // this default mime also triggers iframe downloads
    m = strMimeType || u,
    x = data,
    z = function (a) {
      return String(a);
    },


    B = self.Blob || self.MozBlob || self.WebKitBlob || z,
    BB = self.MSBlobBuilder || self.WebKitBlobBuilder || self.BlobBuilder,
    fn = strFileName || "download",
    blob,
    b,
    ua,
    fr;

  //if(typeof B.bind === 'function' ){ B=B.bind(self); }

  if (String(this) === "true") { //reverse arguments, allowing download.bind(true, "text/xml", "export.xml") to act as a callback
    x = [x, m];
    m = x[0];
    x = x[1];
  }


  //go ahead and download dataURLs right away
  if (String(x).match(/^data\:[\w+\-]+\/[\w+\-]+[,;]/)) {
    return navigator.msSaveBlob ?  // IE10 can't do a[download], only Blobs:
      navigator.msSaveBlob(d2b(x), fn) :
      saver(x, fn); // everyone else can save dataURLs un-processed
  }//end if dataURL passed?

  try {

    blob = x instanceof B ?
      x :
      new B([x], {type: m});
  } catch (y) {
    if (BB) {
      b = new BB();
      b.append([x]);
      blob = b.getBlob(m); // the blob
    }

  }


  function d2b(u) {
    var p = u.split(/[:;,]/),
      t = p[1],
      dec = p[2] == "base64" ? atob : decodeURIComponent,
      bin = dec(p.pop()),
      mx = bin.length,
      i = 0,
      uia = new Uint8Array(mx);

    for (i; i < mx; ++i) uia[i] = bin.charCodeAt(i);

    return new B([uia], {type: t});
  }


  if (navigator.msSaveBlob) { // IE10+ : (has Blob, but not a[download] or URL)
    return navigator.msSaveBlob(blob, fn);
  }

  if (self.URL) { // simple fast and modern way using Blob and URL:
    saver(self.URL.createObjectURL(blob), fn, true);
  } else {
    // handle non-Blob()+non-URL browsers:
    if (typeof blob === "string" || blob.constructor === z) {
      try {
        return saver("data:" + m + ";base64," + self.btoa(blob), fn);
      } catch (y) {
        return saver("data:" + m + "," + encodeURIComponent(blob), fn);
      }
    }

    // Blob but not URL:
    fr = new FileReader();
    fr.onload = function (e) {
      saver(this.result, fn);
    };
    fr.readAsDataURL(blob);
  }
  return true;
}

export function saver(url, fn, winMode) {
  var D = document, a = D.createElement("a")
  if ('download' in a) { //html5 A[download]
    a.href = url;
    a.setAttribute("download", fn);
    a.innerHTML = "downloading...";
    D.body.appendChild(a);
    setTimeout(function () {
      a.click();
      D.body.removeChild(a);
      if (winMode === true) {
        setTimeout(function () {
          self.URL.revokeObjectURL(a.href);
        }, 250);
      }
    }, 66);
    return true;
  }

  //do iframe dataURL download (old ch+FF):
  var f = D.createElement("iframe");
  D.body.appendChild(f);
  if (!winMode) { // force a mime that will download:
    url = "data:" + url.replace(/^data:([\w\/\-\+]+)/, u);
  }


  f.src = url;
  setTimeout(function () {
    D.body.removeChild(f);
  }, 333);
}//end saver
/* end download() */
